EP2058428A1 - Dryer with heat pump - Google Patents

Abstract

The dryer (1) has a drying chamber (9) having an air duct for guiding process air through the chamber, and a heat pump (2, 3, 4) with a heat sink in the air duct and through which air can flow in an outlet air direction for cooling down the air. A heat source is provided and heats up the process air. The outlet air direction and the inlet air direction are parallel to one another. The heat sink and the heat source are in a plane perpendicular to the outlet air direction and to the inlet air direction alongside one another.

Description

The invention relates to a dryer with a drying chamber for objects to be dried, which comprises a process air duct for guiding process air through the drying chamber and a heat pump with a arranged in the process air duct and along an exhaust direction of the process air flow through the heat sink for cooling the process air and in the process air arranged and along a Zuluftrichtung flowed through by the process air heat source for heating the process air has.

Such a vented dryer is apparent from a database "Patent Abstracts of Japan" removable excerpt from the publication JP 2004 089415 A ,

Dryer for laundry and the like items are usually designed as exhaust air dryer or condensation dryer. In the exhaust air dryer, a stream of air from an environment of the dryer is sucked in, heated, passed over the objects to be dried and then discharged as "exhaust air" from the dryer. This exhaust air contains all the moisture removed from the objects to be dried and therefore can not be easily released into a building, as this moisture would be reflected in it; rather, the exhaust air must be removed from the building by means of a corresponding exhaust hose. This is a constructive disadvantage of the exhaust air dryer, which on the other hand is quite simple and thus can be cheaply marketed. A condensation dryer, whose operation is based on the condensation of the guided by means of closed circuit process air from the objects to be dried moisture, does not need a hose for discharging the moisture-laden process air, since stored in him the condensed moisture as a liquid and after completion of drying can be used in an internal bathroom or an internal laundry of a larger residential complex. All this applies both to tumble dryers designed specifically for drying laundry and to so-called laundry dryers, namely appliances that can both wash and dry laundry. Any subsequent reference to a "tumble dryer" therefore applies both to a device intended for drying and likewise for washing and drying.

In an exhaust air dryer, the air laden with moisture after passing through a laundry drum is passed out of the dryer, heat recovery generally not taking place. From the aforementioned excerpt and the document DE 30 00 865 A1 In each case an exhaust air dryer with heat recovery is known. In an exhaust air dryer with heat recovery, ambient air (of, for example, 20 ° C. and 60% relative humidity, so-called supply air) flows into an air-to-air heat exchanger or a heat pump, where it is heated while the warm process air coming from the drying chamber cools down. In the heat exchanger (eg air-air heat exchanger), the moist process air is cooled, so that the water contained in the moist process air condenses. Depending on the cooling capacity or the heat exchange, condensate is produced which is collected or pumped away in a container (condensate tray) for later disposal.

Both in a conventional vented dryer and in a conventional condensation dryer, the heat supplied to the process air is largely lost. In an exhaust air dryer, the heat is dissipated with the laden with moisture from the objects to be dried process air, in a condensation dryer, the heat passes through a heat exchanger in a cooling medium, usually cooling air from the environment of the dryer and is thus lost equally.

In the DE 40 23 000 C2 a tumble dryer with a heat pump is described, in which a supply air opening is arranged in the process air channel between the condenser and the evaporator, which is closable with a controllable closure device.

In the DE 197 38 735 C2 a condensation dryer with a closed drying air circuit is described, which is equipped with a heat pump. The heat pump is designed as a device operating according to the absorber principle, the absorber of which forms a third heat exchanger, the primary circuit of which flows through a refrigerant, and the second heat exchanger via its secondary circuit outgoing drying air is fed back to the secondary circuit of the first heat exchanger.

Moreover, in the DE 43 06 217 B4 a program-controlled dryer described in which the process air is guided by means of a blower in a closed process air duct in which are arranged in a certain way closure devices. Depending on the operating state (heating phase, laundry drying phase, reaching the maximum permissible temperature), the closure devices are actuated suitably.

In a condensation dryer equipped with a heat pump, the cooling of the warm, moisture-laden process air and the condensing out of the moisture contained essentially take place in a heat exchanger referred to below as the first heat exchanger of the heat pump, in particular an evaporator, where the heat transferred to evaporate an in the heat pump circulating refrigerant is used. Such refrigerant vaporized due to the heating is supplied via a compressor, a second heat exchanger of the heat pump, hereinafter referred to as "heat source" and here a condenser for the refrigerant, where heat is released due to the condensation of the gaseous refrigerant, which in turn Heating the process air before entering the drum is used. The liquefied refrigerant passes through a throttle, which reduces its pressure, back to the evaporator to evaporate there, with renewed absorption of heat from the process air.

In the present case, as a heat pump to understand any unit comprising a heat sink, a heat source and means for transferring heat, which has been absorbed in the heat sink, to the heat source, where this is optionally discharged to the heat sink changed temperature level again. There are known such aggregates, which work with cyclic evaporation and liquefaction of a refrigerant, which is usually a fluorinated hydrocarbon; this is a compressor unit as described above. This unit usually works optimally in a certain temperature range. Other embodiments of heat pumps are known, for example, an embodiment in which a Working medium such as water from a suitable substrate, in particular a zeolite, is cyclically adsorbed and desorbed.

In all known embodiments, however, the cleaning of the components of the heat pump, in particular the heat sink, consuming. Such components usually can not be installed so that they can be easily removed for their cleaning, as is well known for the heat exchanger of a conventional condensation dryer; The reason for this is that, in particular in the case of a compressor unit, the cycle of the refrigerant must not be separated in order to prevent refrigerant from escaping from it or from reaching it. The accessibility to the components may also be very limited, which requires significant effort to be able to access the components for maintenance or cleaning.

It is an object of the present invention to provide a dryer in which the accessibility to components of the heat pump can be improved.

This object is achieved by a dryer, which has the features of the independent claim. Preferred embodiments of the invention are subject matters of the dependent claims.

A dryer according to the invention with a drying chamber for objects to be dried has a process air guide for guiding process air through the drying chamber and a heat pump cycle with a arranged in the process air guide and along a direction of exhaust air flow through the heatable heat sink for cooling the process air and arranged in the process air guide and along a Zuluftrichtung of the process air throughflowable heat source for heating the process air has; In this case, the exhaust air direction and the supply air direction are substantially parallel to one another, and the heat sink and the heat source are arranged next to one another in a plane substantially perpendicular to the exhaust air direction and to the air supply direction.

By this configuration, the easier accessibility can be ensured, and it is thereby cleaning operations or other checks and the like lower costs possible. The dryer is designed in particular as a vented dryer. A juxtaposed arrangement of said components is understood to mean a positioning in which these components are arranged side by side and without overlapping in a spatial direction perpendicular to the viewing direction when viewed in a spatial direction on the domestic appliance with substantially identically oriented longitudinal axes, a longitudinal axis being the direction , in which the component under consideration is flowed through by the process air, is to be understood.

Preferably, the heat sink and the heat source are arranged side by side in a front view of the domestic appliance. Especially by this specification, the accessibility to these two components is significantly improved.

The heat sink and the heat source are arranged in particular spaced next to each other.

Preferably, in the dryer according to the invention, the heat sink is an evaporator for a refrigerant circulating in the heat pump, and the heat source is a condenser for the refrigerant. This means that in the context of this preferred embodiment, the heat pump is a compressor unit.

Preferably, a flap is arranged on a wall of the domestic appliance, through which at least the heat sink or the heat source, in particular the heat sink and the heat source, are accessible. In addition to the intended specific positioning of the two components next to each other can be ensured by this wall-mounted arrangement also easy accessibility over the flap. By only a single flap is provided by the opening of both components are simultaneously accessible for cleaning or maintenance purposes, a particularly advantageous embodiment can be provided. In particular, the at least one flap, in particular the single flap, is formed on a front wall of the domestic appliance.

In particular, a filter is arranged in the flow direction of the process air in front of the heat source. In particular, this filter is arranged non-destructively detachable, so that it can be reversibly removed and replaced, or by another Filter can be replaced. This effectively filters dust and other particles from the dryer's ambient air in front of the heat source and effectively purifies the process air, ensuring long-term full functionality of the heat pump.

Fig. 1

eine schematische Draufsicht auf ein Ausführungsbeispiel eines bekannten Trockners;

Fig. 2

eine schematische Draufsicht auf ein Ausführungsbeispiel des Trockners; und

Fig. 3

ein schematisches Blockschaltbild des Trockners gemäß Fig. 2.

Embodiments of the invention are explained below with reference to the schematic drawing. Show it:

Fig. 1

a schematic plan view of an embodiment of a known dryer;

Fig. 2

a schematic plan view of an embodiment of the dryer; and

Fig. 3

a schematic block diagram of the dryer according to Fig. 2 ,

In the figures, identical or functionally identical elements are provided with the same reference numerals.

In Fig. 1 The accompanying drawing is shown in a schematic plan view of a known dryer 1 with heat pump 3, 4, 5, 10, wherein the heat pump comprises a condenser 2 as a heat source 2, a compressor 3 and an evaporator 4 as a heat sink 4. The heat pump 3, 4, 5, 10 is thus a compressor unit; the throttle 10 is in for clarity Fig. 1 not shown, but see Fig. 3 , Other embodiments of the heat pump 3, 4, 5, 10 are conceivable. The evaporator 4 and the condenser 2 are arranged in an open process air guide P of the dryer 1; the dryer 1 is therefore an exhaust air dryer 1 with heat pump 3, 4, 5, 10th

In the partial view of the FIG. 1 the flow directions of the process air in the dryer 1 are indicated, namely the Zuluftrichtung Z and the exhaust air direction A, in this regard via a front wall 5 of the dryer 1 sucked through a fan 6 via the condenser 2 ambient air and within the process air P along the Zuluftrichtung Z by the Condenser 2 is passed. After the subsequent flow through the blower 6 and the (in Fig. 1 not shown, but see Fig. 3 ) Drum 8, the process air along the exhaust direction A is passed through the evaporator 4 and discharged at the back 7 into the environment. The dryer 1 is therefore designed as a vented dryer. As shown in the illustration Fig. 1 it can be seen are the condenser 2 and the evaporator 4 in front viewing direction, that is, in the viewing direction on and through the front wall 5 of the condensation dryer 1, arranged one behind the other and positioned with respect to their arrangement with respect to the flow direction almost at right angles to each other. Since in an exhaust air dryer, the condenser 2 and the evaporator 4 for heat recovery from the exhaust air of the dryer 1 in terms of space and separately must be connected to air channels of the process air P, this arrangement is rather complex in terms of their installation. In addition, there are different configurations for the guidance of the process air, depending on whether it is a "pressing system", ie a process air fan 6 sitting in the flow direction in front of the drum 8 or the largest pressure losses are in the flow direction behind the fan wheel 6, or is a "sucking system" in which the conditions are correspondingly inverse. Fig. 1 shows in this regard an oppressive system.

In addition to the in Fig. 1 shown rectangular arrangement of the condenser 2 and the evaporator 4 may also be provided beyond that these two components are arranged one behind the other offset from one another and no rectangular arrangement is provided to each other.

In Fig. 2 is a trained as exhaust dryer dryer 1 shown in a schematic plan view, with only the essential components for the explanation of the embodiment are shown. The dryer 1 comprises a heat pump circuit 2, 3, 4, 10 with a condenser 2, a compressor 3 and an evaporator 4, wherein the condenser 2 and the evaporator 4 are arranged in the process air guide P. A blower 6 sucks the process air via the condenser 2 and corresponding air channels of the process air guide P according to the arrow along the Zuluftrichtung Z in the functioning as a drying chamber drum 8 (see FIG. 3 ). After exiting the drum 8, the moisture-laden process air is discharged according to the arrow along the exhaust direction A through the evaporator 4, and after exiting the evaporator 4 via the rear wall 7 from the dryer 1 in its surroundings.

Due to the guidance of the process air through the open process air P, the dryer 1 is properly called exhaust air dryer; but it is to be noted that it is in This dryer 1 can still give condensation of moisture: At the evaporator 4, the effluent from the objects to be dried process air is cooled, therefore there is to be expected condensation of moisture. It is therefore necessary to take precaution to catch accumulating condensate. Unless otherwise stated, such condensate can be conventionally collected in a sump for later disposal. Corresponding means are generally known; they are not shown here for the sake of clarity.

In the embodiment according to Fig. 2 For example, the condenser 2 and the evaporator 4 are arranged side by side in a viewing direction on the front wall 5 and thus when viewed in the y direction. In addition, the condenser 2 and the evaporator 4 in the x-direction spaced from each other, wherein in particular it is also provided that the positioning of the condenser 2 and the evaporator 4 is formed so that their longitudinal axes, which extend in the y-direction and both the Zuluftrichtung Z and the exhaust air direction A correspond, are arranged parallel to each other. The condenser 2 and the evaporator 4 are thus in a plane which is perpendicular to Zuluftrichtung Z and exhaust air direction A, side by side. The process air guide P is designed so that the flow directions of the process air through the evaporator 4 and the condenser 2 are parallel and equal to each other. It can also be provided that these flow directions through the evaporator 4 and the condenser 2 are provided in parallel and in opposite directions.

Moreover, the condenser 2 and the evaporator 4 are disposed in the dryer 1 adjacent and close to the front wall 5 in the interior. On the front wall 5, a single flap 9 is arranged in the exemplary embodiment, so that both components, namely the condenser 2 and the evaporator 4, are accessible via the front side of the dryer 1 by opening this flap 9. The flap 9 is in Fig. 2 only symbolically represented.

In addition, in the flow direction of the process air in front of the condenser 2 is a reversibly and non-destructively usable and again removable filter 11 (not in FIG. 2 shown, but see FIG. 3 ) arranged.

In Fig. 3 is a schematic block diagram of the dryer 1 according to Fig. 2 shown. The dryer 1 has the drum 8, which is rotatable via a horizontal axis and which is designed as a drying chamber 8. The sucked by the blower 6 from the environment of the dryer 1 ambient air is first passed through the filter 11 and then through the condenser 2. In the condenser 2, the refrigerant flowing in the refrigeration cycle liquefies with release of heat to the process air. The now present in liquid refrigerant is then passed to a throttle 10 and this again to the evaporator 4. As a result, the refrigerant circuit is closed. The further flow of the process air after exiting the condenser 2 has already been the Fig. 2 explained. After leaving the drum 8, the moist process air flows through the evaporator 4. There it is cooled. After leaving the evaporator 4, the process air is discharged to the environment.

The drive of the drum 8 and the blower 6 and 7 via a common motor, which is not shown for the sake of clarity; the common drive is symbolized by an oblique stroke connecting the fan 6 and the drum 8.

Claims (8)

Dryer (1) with a drying chamber (8) for objects to be dried, which a process air guide (P) for guiding process air through the drying chamber (9) and a heat pump (2, 3, 4, 10) with a in the process air guide (P Having arranged along an exhaust direction (A) of the process air flowable through heat sink (4) for cooling the process air and in the process air duct (P) and along a Zuluftrichtung (Z) of the process air can be flowed through the heat source (2) for heating the process air , characterized in that the exhaust air direction (A) and the Zulauftrichtung (Z) are substantially parallel to each other, and that the heat sink (4) and the heat source (2) in a to the exhaust direction (A) and the supply direction (Z) substantially vertical plane are arranged side by side. Dryer (1) according to claim 1, characterized in that the heat sink (4) and the heat source (2) in a front view of the dryer (1) are arranged side by side. Dryer (1) according to one of the preceding claims, characterized in that the heat sink (4) and the heat source (2) are arranged at a distance from one another. Dryer (1) according to one of the preceding claims, characterized in that the heat sink (4) is an evaporator (4) for a in the heat pump (2, 3, 4, 10) circulating refrigerant and the heat source (2) is a condenser (2 ) is for the refrigerant. Dryer (1) according to one of the preceding claims, characterized in that in a wall (5) of the dryer (1) a flap (9) is arranged through which at least the heat sink (4) or the Heat source (2), in particular the heat sink (4) and the heat source (2) are accessible. Dryer (1) according to claim 5, characterized in that the at least one flap (9), in particular the single flap, on a front wall (5) of the dryer (1) is formed. Dryer (1) according to one of the preceding claims, characterized in that in the flow direction of the process air in front of the heat source (2) a filter (11) is arranged. Dryer (1) according to claim 7, characterized in that the filter (11) is arranged detachably.

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